<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var uname = 20;
        var obj = {
            uname: '刘德华',
            say: function () {
                alert(this.uname);
            }.bind(this)
        }
        obj.say()
    </script>
</body>

</html>